X-Git-Url: http://matita.cs.unibo.it/gitweb/?p=helm.git;a=blobdiff_plain;f=matita%2Fmatita%2Fcontribs%2Flambdadelta%2Fstatic_2%2Frelocation%2Flifts.ma;h=1d6225393ab9c483dee902e2184ac9fddd898fd5;hp=54372cf8f4c0333fb8088c96a4b455309e71ec54;hb=d71e53021b0c17e1a00c2d623e7139c6d18069d5;hpb=f9abd21eb0d26cf9b632af4df819225be4d091e3

diff --git a/matita/matita/contribs/lambdadelta/static_2/relocation/lifts.ma b/matita/matita/contribs/lambdadelta/static_2/relocation/lifts.ma
index 54372cf8f..1d6225393 100644
--- a/matita/matita/contribs/lambdadelta/static_2/relocation/lifts.ma
+++ b/matita/matita/contribs/lambdadelta/static_2/relocation/lifts.ma
@@ -356,6 +356,15 @@ elim (IHV1 f) -IHV1 #V2 #HV12
 ]
 qed-.
 
+lemma lifts_push_zero (f): ⬆*[⫯f]#O ≘ #0.
+/2 width=1 by lifts_lref/ qed.
+
+lemma lifts_push_lref (f) (i1) (i2): ⬆*[f]#i1 ≘ #i2 → ⬆*[⫯f]#(↑i1) ≘ #(↑i2).
+#f1 #i1 #i2 #H
+elim (lifts_inv_lref1 … H) -H #j #Hij #H destruct
+/3 width=7 by lifts_lref, at_push/
+qed.
+
 lemma lifts_lref_uni: ∀l,i. ⬆*[l] #i ≘ #(l+i).
 #l elim l -l /2 width=1 by lifts_lref/
 qed.